Testament Posted March 23, 2017 Share Posted March 23, 2017 depends on the setup how much lift pump you need. if you return the fuel from the rail to the main tank it needs to flow more than the high pressure pump or the surge tank will go empty and the high pressure pump will be continuously cavitating as it only gets as much as the lift pump can pump in. not good. if you return from the rail to the surge tank then the lift pump only needs to flow as much as your max injector flow or you may get away with even less depending on the use of the car. if you are never doing sick 11s for minutes at a time the volume of the surge tank will keep you going for [tank volume/max combined injector flow]minutes. generally you can return to the surge tank if your lift pump has plenty of headroom above your normal fuel flow (which it should at idle/low load unless you have a total pinner lift pump), and your surge tank isn't enormous as it will exchange the volume of fuel in the surge tank with fuel from the tank surge tank volume/(lift pump flow - avg idle low load fuel flow) = time to exchange volume of surge tank 2 Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted March 24, 2017 Author Share Posted March 24, 2017 20 hours ago, Testament said: depends on the setup how much lift pump you need. if you return the fuel from the rail to the main tank it needs to flow more than the high pressure pump or the surge tank will go empty and the high pressure pump will be continuously cavitating as it only gets as much as the lift pump can pump in. not good... you silly sausage. ^ This...I think might possibly be happening. I have now got the setup returning from the rails to the tank and the over flow on the surge also returning to the tank. We took the car for a drive to the big smoke that is Motueka. Nothing really wrong with performance and every thing is smooth but with noticable noise from the main pump. I thought it might be low tank volume as I only had 7 litres left. Filled the tank up and noise still there. Got home and climbed under car with engine running. Surge tank is only jus warm to touch so that problem was solved. However the main pump has a noisy cavitation sound. So as much as I thought my Carter lift pump was the boss and was pumping heaps of good volume, the main pump can obviously pump even more. But why the cavitation sounds when the tank is full??? Is the main pump for want of so much fuel that the lift pump cant supply that it then starts to draw air through the overflow pipe which enter the tank nearer the top? Well luckily its going to be a piece of piss to re-route the rail return back to the surge and then block off the extra inlet I had added onto the fuel tank. With this done I am hoping that the surge tank wont get so hot either, having discovered the blocked filter and replacing it which will should give the lift a new lease on life. Plus in other news, related to the above as I thought it was the hot fuel issue causing it, I have fixed the heat soak surging. 1 minute of table changing on that Mat correction thingee before we took off and it seems to be sorted. Having left it outside the steel merchants while I picked up supplies and then outside the supermarket later on and neither time did it lean out after startup. Sweet! I will play with it some more as I think I can get it even better. Interesting to watch the air temps changing with use too. Anything from sitting at 25 degrees when driving along to around 45 degrees after the car has sat for a while turned off. The new table here... 5 Quote Link to comment Share on other sites More sharing options...
NickJ Posted April 23, 2017 Share Posted April 23, 2017 Have the 14.7 wideband kit running well, but the screen lag makes it hard to read while driving, the 0-5V output however made it really easy to feed the output to a much easier to interpret screen. just used 2m of trailer cable for the sensor, which was a good call as it does haul ~3A while running! for less than 100usd you get the kitset and sensor, pretty bloody good really, I then put it in a cheap plastic case and its a very useable setup 2 Quote Link to comment Share on other sites More sharing options...
kws Posted April 23, 2017 Share Posted April 23, 2017 Yeah the 14point7 stuff is pretty good. My Spartan2 has been doing a solid job to tuning the Rover. 1 Quote Link to comment Share on other sites More sharing options...
NickJ Posted April 23, 2017 Share Posted April 23, 2017 Hells yeah, I thought I killed it, was just a connector coming out inside the box, seems very robust otherwise. Have ordered some nice waterproof connectors off ali to set it up fully moveable between cars 1 Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted April 23, 2017 Author Share Posted April 23, 2017 Certainly not the prettiest setup but hell- for that price... crikey. I think I paid over 100 nzd for my o2 sensor alone. What sensor is that kit using? Quote Link to comment Share on other sites More sharing options...
fuel Posted April 23, 2017 Share Posted April 23, 2017 Alex - you could re-locate the air temp sensor to inside the air filter element somewhere, as this is usually where many other factory cars have their IAT sensors (ie Mitsubisi AFMs used by Mitsubishi, Mazda, Ford etc). You could run some extended wiring underneath the pipe and it should still be hidden somewhat. 1 Quote Link to comment Share on other sites More sharing options...
NickJ Posted April 23, 2017 Share Posted April 23, 2017 1 hour ago, yoeddynz said: Certainly not the prettiest setup but hell- for that price... crikey. I think I paid over 100 nzd for my o2 sensor alone. What sensor is that kit using? Nah not pretty at all! but I only intend it to be a setup and trouble shooting tool, not for full time fitment, however there is nothing stopping me from sourcing a standard gauge to feed the 0-5V output to and hiding the box under the dash. It runs a Bosch 4.9 sensor, and by all means appears to be legit, they only sell the sensors cheap if brought with a kit, so w.ith postage its not much of a savings over the hundy they are on the shelf here for Quote Link to comment Share on other sites More sharing options...
Ned Posted April 24, 2017 Share Posted April 24, 2017 Thats cool man! Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted April 26, 2017 Popular Post Share Posted April 26, 2017 I dont have anything in particular to say right now, except for that I've started working at HP Academy in Queenstown. I have learned a mind blowing amount of stuff from Andre and co already. Motec M150 is just some next level shit. Sheezus. With the M150 you can write your own code for the firmware, today we were trying idea of IMAP / EMAP as a load axis. (intake manifold pressure divided by exhaust manifold pressure pre turbo) Which is a bit of a mind bender to me but apparently this compensates for VE changes etc relating to altitude and turbine efficiency way better than just MAP or MGP. Next step is to take the GT86 for a hoon up a mountain and see how well the AFR stays on target. I'm not sure if it's obvious from this post yet but holy crapping Christ. What a company to work for. The other day Tony Quinn's Pikes peak car was in for a tune before heading off again. It runs a VR38DETT mid mounted, runs two turbos > two intercoolers > two plenums (connected with a balance pipe) Looking at the intercoolers with the thermal camera we found a 20 degree temp difference left to right. Some more poking around from there and we found that one of the intercooler hose clamps was loose, so intercooler on that side had lower mass flow so lower temp. TL;DR: This thing is a fucking weapon, Andre got another 100hp out of it just with tuning. Same boost. ~950kg and now ~605hp atw with plenty of head room. Just stopped there because he wasnt sure if it will still be drivable, going to Highlands for testing on Saturday. 27 Quote Link to comment Share on other sites More sharing options...
NickJ Posted April 26, 2017 Share Posted April 26, 2017 Good life choices Mr Roman 3 Quote Link to comment Share on other sites More sharing options...
AllTorque Posted April 26, 2017 Share Posted April 26, 2017 Shit yeah. You will sure learn a lot from Andre. 1 Quote Link to comment Share on other sites More sharing options...
Ned Posted April 26, 2017 Share Posted April 26, 2017 Roman, you know the rules! No posts without graphs allowed... 2 Quote Link to comment Share on other sites More sharing options...
NickJ Posted April 28, 2017 Share Posted April 28, 2017 Made some progress getting the rpm signal to the car, brought an LM2917 IC and put it together, the datasheet and maths was a bit much for after work so I messed about with it until I figured out how it worked. I then rigged up the arduino to generate 5 seconds of 1000rpm followed 5 seconds of 6000rpm as a test signal with a multimeter on the output, its now outputting roughly 1V/1000rpm, just in time for the weekend to try it in the car. 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted April 30, 2017 Share Posted April 30, 2017 Love your work NickJ! I need to get schooled up on some Arduino stuff. Quote Link to comment Share on other sites More sharing options...
NickJ Posted April 30, 2017 Share Posted April 30, 2017 4 hours ago, Roman said: Love your work NickJ! I need to get schooled up on some Arduino stuff. Do it! I really should work with them more often, always so rusty on the coding whenever I do. Bonus is that pretty much everything has been done before in some way online, that its an easy task to copy and paste then change a few lines to suit. Quote Link to comment Share on other sites More sharing options...
Ned Posted April 30, 2017 Share Posted April 30, 2017 You're welcome to message me if you need to tackle something you can't find online 2 Quote Link to comment Share on other sites More sharing options...
Carsnz123 Posted May 6, 2017 Share Posted May 6, 2017 I hate to drag you all away from your conversation about surge tanks and heatsoaking but is there anyone in Christchurch who I can talk to about converting my bike to EFI using a Megasquirt ECU. The main goal it to be able to turbo it some time down the track all on a shoestring budget with parts from questionable sources and negligible reliability. 2 Quote Link to comment Share on other sites More sharing options...
anglia4 Posted May 6, 2017 Share Posted May 6, 2017 I think this fella was doing an EFI turbo c90 or something like that https://www.facebook.com/jonnysspeedshop/ Quote Link to comment Share on other sites More sharing options...
Rookie Posted May 12, 2017 Share Posted May 12, 2017 On 5/6/2017 at 06:12, Carsnz123 said: I hate to drag you all away from your conversation about surge tanks and heatsoaking but is there anyone in Christchurch who I can talk to about converting my bike to EFI using a Megasquirt ECU. The main goal it to be able to turbo it some time down the track all on a shoestring budget with parts from questionable sources and negligible reliability. If you have no money then start reading and do it yourself, there isn't much too it if you follow the instructions, but beware that it is like physics, in that if you just know how to plug numbers into formulas, but don't really understand why, then you will have a much harder time making it work than if you spent a bit of time to learn what each thing actually does. 3 Quote Link to comment Share on other sites More sharing options...
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